A NAS gateway is a NAS (network-attached storage) system in which the storage media are externally attached, typically over a Fibre Channel interface. The external storage might be connected by means of a SAN (storage area network), or it might comprise a stand-alone box shared among multiple servers.
With the use of a NAS gateway, all clients "see" the file serving function as a standard NAS device. The gateway appears as a single folder on every user's computer. If more storage is added to the system, the gateway retains its single-folder interface. A principal advantage of a NAS gateway over traditional disk arrays is theoretically unlimited storage capacity (although, beyond a certain point, the performance degrades). A NAS gateway can also support iSCSI (Internet Small Computer System Interface), an IP-based standard for linking data storage facilities.
NAS gateways have proven useful for networking applications in businesses of all sizes. One example is OnStar, a subsidiary of General Motors that provides subscription-based communications, security, navigation, and remote diagnostics for motor vehicles.